Quality Control Program

ChemValve has an extensive Quality Control Program that is strictly followed for each valve. For all of our products, copies of these documents can be furnished upon request. The Fully Lined Plug Valve and Ball Check Valve lines have specific tests conducted on each and every valve before shipment.

Fully Lined Plug Valve

• 50,000 volt electric discharge (spark tester) test is used to detect any small holes,thin spots, or imperfections in the plastic liner. This is done after the molding operation and after the final machining before assembly to verify that no imperfections are in the resin.
  
  
• The hydrostatic test (shell test) is performed at one and a half times the maximum rated pressure. The hydrostatic test is performed to verify that the valve will perform under pressure.

• The stem leakage test (with nitrogen gas) is performed at one and a half times the maximum rated pressure as an added safety feature. This is a bubble tight test and the valve must pass while being operated.
  
  
• The valve seat leakage test is performed at the maximum rated pressure. This is a hydrostatic test with the acceptance criteria: drop tight for two minutes.

• A valve operating torque test done at the maximum operating pressure at the inlet pressure and at zero gauge pressure as the outlet pressure. This test is performed with a torque wrench. The acceptance criteria are 75% of our published “Break Torque”. This test is to verify that the valve will shut off tight.
  
  
• Copies of documents, for all our products, can be furnished upon request. The fully lined plug valve line has five specific tests conducted on each and every valve before shipment.